Helical pulp grinder



ug- 4, 1954 L.. H. Hr-:ss ErAL 3,143,305

HELICAL PULP GRINDER Filed Oct. 28, 1959 4 Sheets-Shea?l 1 Aug. 4, 19641 H. Hess ETAL. 3,143,305

HELICAL PULP GRINDER Filed oct, ze, 1959 4 sheets-sheet 2 a a/ H.- ess Ed/ @El 5- ug- 4, 1964 1 H. Hass ETAL 3,143,305

HELICAL PULP GRINDER Filed OCT'. 28, 1959 Sheets-Sheet 5 hren/:2F75 3M3s 326 Lloyd Hornboszel oya/ M Hess Aug. 4, 1964 1 H. HEss ETAL HELICALPULP GRINDER 4 Sheets-Sheet 4 Filed Oct. 28, 1959 United States Patent O"ice 3,143,365 HELICAL PULP GENDER Loyal H. Hess and Lloyd Hornhostei,Beloit, Wis., as-

signors to Beloit Iron Works, Beloit, Wis., a corporation of WisconsinFiled Oct. 28, 1959, Ser. No. 849,349 Claims. (Cl. 241-279) The presentinvention relates broadly to the art of pulp production for use in papermanufacture, and is more particularly concerned with new and improvedlog disintegrating apparatus employing conical abrasive means engageablewith axially movable logs, the apparatus featuring in part independentlyoperable, accurately controllable and infinitely adjustable abrasivemeans.

It has heretofore been proposed to support a log to be ground in ahorizontal position upon a pair of spaced non-driven rollers and tosubject the logs to a shredding action by means of a conical grindingwheel, which functions to abrade, rotate and axially advance the logthrough successive grinding stations. While the pulp grinding machine towhich reference was made represents a substantial advance over the priorart, it has been found that numerous improvements can be made therein toenhance the versatilitg of the apparatus to improve upon the eiiiciencyof the pulp grinding operation and to produce pulp stock of higherquality for paper manufacture.

It is accordingly an important aim of the present invention to provide ahelical pulp grinder having as one feature thereof a plurality ofgrinding members each mounted by individual driving means and therebypermitting selective control over the abrading action performed indifferent grinding stations, and further eliminating the necessity ofrelatively cumbersome intermediate drive linkages.

Another object of this invention lies in the provision of 10g abradingapparatus utilizing a plurality of spaced grinding units, each of whichis adjustable in a plurality of different planes to permit accuratecontrol of the force applied for different types of woods being groundas well as use with a wide variety of log diameters, and furtherpermitting relative movement of a particular point on the grindingsurface with respect to the top center of the log whereby longergrinding surface wear is obtained.

Another object of the instant invention is to provide grinding apparatusfor producing pulp from axially advancing logs, and which comprises aplurality of grinding units, means pivotally mounting each of thegrinding units upon a stationary support, and pneumatic means connectingwith the mounting means to pivotaliy swing each grinding unit through anarcuate path toward and away from the logs supported therebeneath.

A further object of the present invention is to provide grindingapparatus of the character described, and which additionally featuresenclosure means for the grinding units to protect the drive means andparticular connecting structure against damage from treating uid used inthe grinding operation, as well as to prevent splashing of adjacentpersonnel by said iluid and pulp contained therein.

An even further object of this invention lies in the provision of pulpgrinding apparatus, and which additionally features vertically andhorizontally adjustable supporting rollers for the logs during thegrinding thereof, whereby logs of varying diameters can be accommodatedand uniform compressive forces exerted thereagainst to assure looseningof the log bers regardless of the log diameter.

Other objects and advantages of the invention will become more apparentduring the course of the following description, particularly when takenin connection with the accompanying drawings.

3,143,395 Eaented Aug. ll, gd

In the drawings, wherein like numerals designate like parts throughoutthe same:

FIGURE l is an end elevational view of grinding apparatus constructed inaccordance with the principles of this invention, and showing thegrinding unit in a position of engagement with the log being ground;

FIGURE 2 is a view similar to FIGURE l, and showing the grinding unit ina raised or retracted position relative to the log;

FIGURE 3 is a fragmentary side elevational view of the present grindingapparatus, illustrating the successive diameter reductions effected upona log during travel axialiy upon supporting rollers;

FIGURE 4 is a sectional view taken substantially along the line IV-IV ofFIGURE l, and showing particularly an exemplary form of stock meanswhich may be employed to limit upward and downward swinging movement ofthe grinding units;

FIGURE 5 is a fragmentary sectional view taken substantially along theline V--V of FIGURE l, and illustrating means for adjusting movement ofthe grinding wheel motor mount with respect to supporting structuretherefor; and

FIGURE 6 is a view taken substantially along the line VI-Vl of FIGURE 1,and showing in further detail vertical and tiltable adjusting means asprovided in accordance with the novel concepts of this invention.

Briefly stated, grinding apparatus as herein provided embodies aplurality of individual abrading mechanisms wmch act upon spacedlocations of rotating and axially advancing logs supported by rollermeans having vertical and horizontal adjustability as a feature thereof.The rollers and the logs carried thereon are partially submerged in abath of treating fluid housed in a trough, the treating uid having amongits purposes a loosening of the log fibers to facilitate separationduring the grinding operation. The trough is enclosed when the logabrading is taking place, and the enclosure means protects the grindingunits and persons in the area adjacent thereto against splashing effectsfrom wet pulp and/or treating solution.

Each grinding unit is preferably mounted by a Stationary support carriedby the trough structure, and the stationary support receives pivot meansmounting a swingable stop member which cooperates with a stationary stopmember fixed to the supporting structure. The swingable stop memberconnects with supporting means mounting the grinding units andassociated with the supporting mems are pneumatic motive means orcylinders, the actuation of which swings the movable stop member,connecting supporting means and associated abrading surfaces about thefixed pivot on the stationary support to raise or lower the grindingsurfaces as desired.

Each grinding surface is preferably in the form of a conical grindingwheel mounted by an individual motor, which is in turn connected to thesupporting means and features vertical adjustably relatitve thereto.Each grinding motor and the grinding wheel carried thereby is furtheradjustable in a direction generally transverse to the log top center tochange the point of tangential contact of the grinding surface or wheelon the log periphery. Additionally, each grinding motor is tiltablyadjustable upon the supporting means to provide a further variation inthe point of tangential contact of the grinding surface on the log, aswell as a fine control over the force applied to the log during thegrinding operation. Numerous other features of the invention will becomemore apparent as the description now proceeds.

Grinding apparatus provided in accordance with the principles of thisinvention is designated generally in FIGURE l by the legend A, andcomprises a supporting base 10 which may be of cement construction andformed to provide a longitudinally extending central portion 11 atopposite sides of which is a pair of trough portions 12 and 13 whereinmay be located a treating fluid in a quantity suiiicient to till thetrough portions to the level indicated at L in FIGURE 1. The supportingbase is further shaped to provide an upright side wall 14 mountingthereon a door or wall member 15 which may be vertically slidable toprovide access to the operating parts of the grinding apparatus A.

The central portion 11 of the base or foundation 10 is contoured tosupport mounting means 16 in the form of a table or pedestal forconveying means generally designated as 17 and 18. The conveying meanscomprise a plurality of pairs of bracket members 19 and 20, which asindicated in FIGURE 3 may be mounted in end to end abutting relation.Each bracket member is provided with a flange portion 21 transverselyslotted as at 22 to provide horizontal adjustment, each of the angeportions 21 receiving therebeneath shims 23 to permit verticaladjustment of the conveying means 17 and 18. The ange portions 21receive therethrough screw means 24 threaded into the pedestal 16, andas shown, the shims 23 are slotted in the manner of the bracket flangeportions 21. Suitable means are provided to continuously urge thebracket members 19 and 20 toward one another, and such means may takethe form of springs 25, although of course other means can be used forthis purpose. It will now be seen that the conveyor means 17 and 18feature both vertical and horizontal adjustability, so that logs ofvarying diameters can be accommodated and at the same time suiiicientforces exerted against the logs to effect compression thereof, wherebydue to said compression the iibers of the logs are loosened and fiberremoval during grinding facilitated.

Each bracket 19 and 20 of the conveyor means receives shafts 26 mountingconveyor rollers 27 and 28. The conveyor rollers are freely rotatableand are generally smooth surfaced, although at the inlet end of theapparatus A the rolls may be driven and may have grooves formed therein,as indicated by the numeral 29 in FIGURE 3, to assist in axial movementof the log therealong. As shown in FIGURE 1, the conveyor rollers 27 and28 receive log W therebetween and are continuously in contact with thelog periphery at a pair of spaced points thereabout. It is to be furtherobserved from FIGURE 1 that the log W is submerged to approximatelyone-ha1f its diameter in the treating solution, and that the conveyorrollers 27 and 28 are almost entirely submerged. By this arrangement,the log W is continuously subjected to the effects of the treatingfluid, which functions to dissolve the lignins in the log whereby berremoval is considerably facilitated.

The opposite side of the base 19 is provided with a relatively flat basesurface 30 and erected therefrom is a pair of spaced stationary wallmembers 31 and 32. A plurality of pairs of wall members 31 and 32 arespaced along the length of the grinding apparatus A, and said membersprovide a pivotal support for each of the grinding units in the mannernow to be described.

It is to be seen upon reference to FIGURE 4 that the stationary wallmembers 31 and 32 are turned inwardly at 31a-b and 32a-b to receivebearings 33 providing support for a pivot shaft 34. Corotatably mountedupon the pivot shaft 34 and spaced inwardly of the opposite ends thereofby the flange portions 31a-b and 32a-b is a sleeve portion 35 of a stopmember generally designated at 36 and having a yoke portion 37 integralwith the sleeve portion 3S. At spaced locations thereon the yoke portion37 is formed with a pair of stop portions 38 and 39, which cooperatewith later described xed structure on `the wall members 31 and 32 tolimit upward and downward movement of the grinding units.

Each wall member 31 and 32 may carry upon the inner surfaces thereof arigidifying rib 31C and 32e, and it may be seen from FIGURE 4 that theseribs terminate configurations, and in the exemplary form illustrated insection in FIGURE 4 said stop member may have a downwardly bowed portion41b connecting with the ange portions 41a and a generally uprightportion 41C having a generally T-shaped stop portion 41d formed thereon.

The means to rotate the grinding units upwardly andV downwardly in anarcuate path about the pivot point 34 between the positions of FIGURES land 2 are preferably pneumatic, and may be seen to take the form of apair of air cylinders 42 and 43. The cylinders 42 and 43 are attached attheir inner ends to the opposite ends of the iixed stop member 41, andthe opposite end of the cylinder 43 is attached for movement to a wallportion 44 connecting with the movable stop member 36. The opposite endof the air cylinder 42, on the other hand, is connected to a pair ofspaced elbow or hinge members 45 and 46 integral with a cup-shapedhousing portion 47, which itself is secured to or integral with themovable stop member 36 for swinging movement therewith. While theoperation of the instant apparatus will be described in detailhereinafter, it may be noted at this point that the admission of airpressure to the air cylinder 42 rotates or swings the movable stopmember 36 and structure connecting therewith in a counter-clockwisedirection until the iixed stop portion 41d on the stop member 41contacts or abuts with the stop portion 39 on the movable stop member36. Ination of the air cylinder 43, on the other hand, causes movementas shown in FIGURE 2 to raise the grinding apparatus, and the extent ofupward movement is limited by contact of the ixed stop portion 41eagainst the movable stop portion 3S.

The spaced elbow members 45 and 46 receive therebetween a hinge oriiange portion 48 (FIGURE 6) fixed to a plate member 49. The elbowportions 45 and 46 receive therethrough bolt means 5t) and S1 havinglock nuts 52 associated therewith, and as shall be described later, theelbow portions 45 and 46, the ilange or ear portion 48 and the bolt andnut means 50-42 provide a ne tiltable adjustment of the grinding units.

Mounted in face to face relation With theplate member 49 is a platemember 53 to which connects a motor bracket S4 supporting therein motormeans 55, each of which is provided with a shaft 56 carrying thereon agrinding wheel or surface 57, illustrated in its preferred form asgenerally conical.

The motor mounting plate member 53 is adjustably connected to the platemember 49 by means of a bolt 58 threadably received in the plate member49 and passing through a flange portion 59 on the plate member 53. Itmay be noted from FIGURE l that the bolt means 58 is generally of lesserlength than the threaded bore 6) receiving said bolt means, for thepurpose of providing an adequate range of vertical adjustment of theplate member 53 with respect to the plate member 49. Upon reference toFIGURE 5 it may also be noted that the plate member 49 has formedthereon a tongue portion 49a slidable in a groove 53a in the plate 53 tothereby provide guiding means during vertical adjustment.

Upon reference now to FIGURES 1 and 6, it is to be observed that theplate members 49 and 53 are further attached one to the other by aplurality of bolt means or the like 60 threaded from the plate member 49into the plate member 53. The plate member 49 is provided with aplurality of slots 61 therein which are of a length generallycorresponding to the extent of adjustment of the plate member 53relative to the plate member 49 by means of the bolt 58. The platemember 49 is shown in FIG- URE 6 as canted or tilted toward the inletend of the grinding apparatus, and this annular displacementis preerredin order to similarly dispose the grinding wheel 57 to produce from thelog W a relatively longer and thereby higher quality liber.

Referring now again to FIGURE 5, the plate member 49 has formed thereonan outwardly extending annular portion 49h and 49C received between theinner wall surfaces of the cup-shaped housing portion 47. The housingportion 47 is provided with a pair of ear portions 47a and 471; passagedwith slotted openings 47C therein receiving stud means or the like 62 toeffect an attachment between the housing portion 47 and the plate member4?. The stud means 62 receive locking nuts 63 therein, the adjustment ofwhich permit adjustment of the location of a particular point on thesurface of the grinding wheel 57 with respect to the top center of thelog W. This provides, among other advantages, a change in the particularportion of the grinding surface effecting a shredding action to reducewear of the grinding surface. As is apparent, the relative length of theear portion 43 received between the ilange portions 45 and 46, and whichmeans were described as e`ecting a fine tilting adjustment, is such thatthe plate member 49 and structure connecting therewith may be movedoutwardly by the adjusting means 62 and 63 a sufficient distance withoutthe ear portion 4S being out of contact with the bolt means 5l and 52pressing thereagainst. Further, it may be seen from reference to FIGURES5 and 6 that the slotted openings 47C in the ear portions 47a of thehousing 47 are of sutlicient width with respect to the diameter of thestud means 62 so that there is no interference when tiltable adjustrnentis eected by the ear or tongue portion 48, elbow portions 45 and 46, andbolt and locking means Sti-42.

It was earlier noted in connection with FIGURE l that the side wallstructure l5 provides a splash guard to prevent treating fluid and/ orpulp from being cast into the area outwardly of said wall structureduring the grinding operation. The side wall structure l5 may bevertically or horizontally movable to provide access to the grindingwheel 57, motor means 55 or other structure of the grinding apparatus A.In addition to the enclosure portion l5, the grinding apparatus Aincorporates splash guard means which protects the motor means and theother structure described. In this connection, it may be seen from FIG-URE l that the motor means 55, the plate members 49 and 53, the housingportion 47 and the pivotal connection 34 and means adjacent thereto areprotected by an enclosure portion generally designated at 65.

The enclosure means 65 may comprise a top wall portion 66 connectingwith a side Wall portion 67 having an outwardly turned portion 67a whichcooperates with a similar portion 68a on an inclined wall portion 68 toclamp therebetween rubbing seal means 69 which may be constructed ofrubber. The enclosure means 65 further comprises a bottom wall portion70 having an upwardly turned portion 7 9a in rubbing contact with sealmeans 71, also of rubber, and held between clamp means 72. One portionof the clamp means 72 attaches with a further wall portion 73 of theenclosure means 65, and it may be seen that the wall portion 73 curvesdownwardly to terminate at the upper wall surface 3i) of the foundationlt?. Welding techniques, screw means or the like may be employed toattach the various wall portions of the enclosure means 65 to thestructure housed thereby.

Experience has indicated that the grinding wheel 57 should at all timesduring the shredding operation be maintained free of adherent pulpfibers, and for this purpose there is provided in this apparatus nozzlemeans 75 supported by the enclosure wall portion 7i?, and directedtoward the grinding wheel surfaces to iiush the same of ibers. Hot wateris normally employed, although steam may also be utilized and thecleansing iluid may have a solvent added thereto to assist in looseningof the iibers during grinding. Normally, however, the solvent actionwould be performed by use of treating uid in the trough portions 12 and13 in rolling Contact with the conveyor rollers 27 and ZS and the log Wsupported thereby. In this regard, it may be found desirable topressurize the trough to effect a chemical cooking of the pulp receivedtherein. This can readily be effected by suitable strength-l ening ofthe trough structure and the enclosure means to withstand pressures ofthe order required. Pressurizing of the trough would then renderunnecessary chemical cooking in a subsequent processing step, whichwould by conventional practices be performed in a location removed fromthe grinding apparatus.

While it is believed that the operation of the instant apparatus isapparent from the preceding description, a brief summary will now begiven. The log to be ground, and from which the bark would normally beremoved in an earlier processing step, is supported upon thefreewheeling rollers 27 and 28, and upon entry of the log into thegrinding zone beneath the abrasive wheel 57, a rotational and axiallyadvancing force is applied to the log by reason of the conicalconfiguration employed. The conical grinding wheels 57 not only abradethe surface of the log in a generally helical fashion to a particulardepth, but also compress the log surface to effect liber loosening.Specically, by virtue of the weight of the grinding wheel and the motorsupporting said wheel, as well as the connecting mounting structure, asubstantial force is applied against the log to effect a compression,and as the log rotates in contact with and beneath the grinding wheels,a further compression is provided by the conveyor rolls 27 and 2S.Accordingly, the log is subjected to an alternating compression anddecompression, the latter action taking place on that portion of the logperiphery which is not directly contacted by either the grinding wheelor the conveyor rolls. As stated, the weight of each grinding unitapplies a substantial force, and additional compressive action may beimparted by the air cylinders 42, whereby a substantial loading is atall times present.

The grinding wheels 57 are preferably canted in the direction of theinlet end of the apparatus A to provide a more positive grinding actionand to in effect lift the iibers from the logs during the grindingoperation. The grinding wheels 57 rotate in a counter-clockwisedirection to rotate and simultaneously axially urge the logs along theconveyor rollers 27 and 2S in free rolling contact therewith.

The force applied to the logs by the grinding wheels 57 may of course bevaried by the air cylinders 42, so that a uniform compressive force isexerted regardless of the particular type of wood being ground. Further,should the type of wood vary or the initial diameter of the logs to beground be diiferent, a fine tiltable adjustment of the grinding wheels57 with respect to the logs may be obtained by adjustment of the earportion 48 with respect to the elbow members 45 and 46.

Additionally, a relatively greater depth of cut can be effected byvertical adjustment of the grinding wheels 57, and as earlier noted,this is accomplished by raising or lowering the plate member 53 withrespect to the plate member 49 by means of the adjusting bolt 58, andfurther by means of the bolts 60 passing through the plate 49 into theplate 53. And as was noted, should adjustment in a generally transversedirection be desired to reduce grinding wheel wear, the stud means 62can be varied to increase or decrease the distance of the plate member49 relative to the housing portion 47.

The action of the novel stop means herein provided was earlierdescribed, and it can be seen upon comparison of FIGURES l and 2 thatination of the air cylinders 42 lowers the grinding wheels, motor meansand all movable structure connecting therewith to a down or 10g engagingposition. At this time, there is no air input to the cylinders 43, andthe latter cylinders are only actuated when it is desired to raise thegrinding units from the position of FIGURE 1 to that of FIGURE 2. Whenin the down position, the movable stop means 36, and particularly thestop portion 39 thereon, abuts against the fixed stop portion 41d on thestop member 41 to limit the downward movement. Raising of the grindingunits by inflation of the air cylinders 43, on the other hand, islimited by contact of the movable stop portion 3 with the fixed stopportion 41d, as clearly indicated in FIG- URE 2.

It may now be seen that applicant has provided grinding apparatuswherein the motor means and grinding wheel supported thereby areadjustable in a plurality of different planes, permitting the control offorce applied for different types of woods and further permitting use ofthe apparatus with a wide variety of log diameters. Variation in logdiameters is further accommodated by the vertical and horizontaladjustability of the conveyor means 17 and 18, so that at all times aconstant compressive force is applied against the log W during grinding.All operating parts which might possibly be damaged by contact with thetreating fluid are shielded by the enclosure means 65, and as well,splashing outwardly from the grinding zone is prevented by the wallstructure 15. By provision of motor means for each grinding wheelindependent control is achieved, whereby among other advantages eachgrinding station may be adjusted to particular conditions. Further,particular circumstances may render it desirable to operate onlyparticular grinding stations, and this is readily accommodated by theapparatus herein disclosed. By this apparatus the logs are successivelyreduced in diameter and this is illustrated in FlGURE 3 which shows thesequential tapering grinding action performed by the invention.

It is to be understood that various changes and modi.

fications may be effected in the apparatus disclosed without departingfrom the novel concepts of the present invention.

We claim as our invention:

l. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, means to drivingly support each of thegrinding surfaces independently of the other grinding surfaces,stationary means pivotally mounting the drive support means, andpneumatic means connected to the drive support means and to thestationary means to individually swingably move said support means in anarcuate path downwardly and upwardly to locate the grinding surface onsaid support means into and out of engagement with the logs.

2. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, motor means to drivingly support eachof the grinding surfaces independently of the other grinding surfaces,mounting means for said motor means, support means connected to saidmounting means, a movable stop assembly having stop means thereon andconnected to the support means, stationary means having stop meansthereon and pivotally mounting the movable stop assembly, and pneumaticmeans connected to the movable stop assembly and to the stationary meansto move said stop assembly about its pivotal connection with thestationary means to swing the grinding surface, motor means, mountingmeans and support means in a raising and lowering direction, the movablestop means contacting the stationary stop means at the extent of raisingand lowering directions to limit movement of the grinding surfaces.

3. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, means to drivingly support each of thegrinding surfaces independently of the other grinding surfaces,stationary means pivotally mounting the drive support means, pneumaticmeans connected to the drive support means and to the stationary meansto individually swingably move said support means in an arcuate pathdownwardly and upwardly to locate the grinding surface on said supportmeans into and out of engagement with the logs, and means connected tothe drive support means to vertically adjust said drive support meansand the grinding surface thereon relative to the logs on the conveyormeans.

4. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of indi vidually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, means to drivingly support each of thegrinding surfaces independently of the other grinding surfaces,stationary means pivotally mounting the drive support means, pneumaticmeans connected to the drive support means and to the stationary meansto individually swingably move said support means in an arcuate pathdownwardly and upwardly to locate the grinding surface on said supportmeans into and out of engagement with the logs, and means connected tothe drive support means to adjust said drive support means and thegrinding surface thereon in a generally transverse direction relative tothe conveyor means.

5. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, means to drivingly support each of thegrinding surfaces independently of the other grinding surfaces,stationary means pivotally mounting the drive support means, pneumaticmeans connected to the drive support means and to the stationary meansto individually swingably move said support means in an arcuate pathdownwardly and upwardly to locate the grinding surface on said supportmeans into and out of engagement with the logs, and means connected tothe drive support means to tiltably adjust said drive support means andthe grinding surfaces thereon in generally the dlrection of swingablemovement of the support means relative to the stationary means.

6. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs durlng travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, motor means to drivingly support eachof the grinding surfaces independently of the other grinding surfaces,mounting means for said motor means, support means connected to themotor mounting means, a stationary means pivotally mounting the supportmeans, and pneumatic means connected to the support means and to thestationary means to individually swingably move said support means in anarcuate path downwardly and upwardly to locate the grinding surface onsaid support means into and out of engagernent with the logs.

7. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, means to drivingly support each of thegrinding surfaces independently of the other grinding surfaces,stationary means pivotally mounting the drive support means, pneumaticmeans connected to the drive support means and to the stationary meansto individually swingably move said support means in an arcuate pathdownwardly and upwardly to locate the grinding surface on said supportmeans into and out of engagement with the logs, and enclosure means forthe conveyor means and drive support means to prevent spraying of pulpinto the areas adjacent the conveyor means to prevent damage to saiddrive support means.

8. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, means to drivingly support each of thegrinding surfaces independently of the other grinding surfaces,stationary means mounting the drive support means, and pneumatic meansconnected to the drive support means and to the stationary means toindividually move said support means downwardly and upwardly to locatethe grinding surface on said support means into and out of engagementwith the logs.

9. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, means to drivingly support each of thegrinding surfaces independently of the other grinding surfaces,stationary means pivotally mounting the drive support means, andactuation means connected to the drive support means and to thestationary means to individually swingably move said support means in anarcuate path downwardly and upwardly to locate the grinding surface onsaid support means into and out of engagement with the logs.

10. Apparatus for grinding logs to produce pulp therefrom, comprisingconveyor means for supporting the logs during travel along saidconveyor, a plurality of individually operable grinding surfaces toabrade the logs at spaced locations thereon and while said logs aresupported by the conveyor means, means to drivingly support each of thegrinding surfaces independently of the other grinding surfaces,stationary means pivotally mounting the drive support means, actuationmeans connected to the drive support means and to the stationary meansto individually swingably move said support means in an arcuate pathdownwardly and upwardly to locate the grinding surface on said supportmeans into and out of engagement with the logs, and means connected tothe drive support means to vertically adjust said drive support meansand the grinding surface thereon relative to the logs on the conveyormeans.

References Cited in the file of this patent UNITED STATES PATENTS2,377,991 Carlson June 12, 1945 2,492,684 Coates Dec. 27, 1949 2,912,023Baker Nov. 10, 1959 FOREIGN PATENTS 359,688 Germany Sept. 25, 1922

1. APPARATUS FOR GRINDING LOGS TO PRODUCE PULP THEREFROM, COMPRISINGCONVEYOR MEANS FOR SUPPORTING THE LOGS DURING TRAVEL ALONG SAIDCONVEYOR, A PLURALITY OF INDIVIDUALLY OPERABLE GRINDING SURFACES TOABRADE THE LOGS AT SPACED LOCATIONS THEREON AND WHILE SAID LOGS ARESUPPORTED BY THE CONVEYOR MEANS, MEANS TO DRIVINGLY SUPPORT EACH OF THEGRINDING SURFACES INDEPENDENTLY OF THE OTHER GRINDING SURFACES,STATIONARY MEANS PIVOTALLY MOUNTING THE DRIVE SUPPORT MEANS, ANDPNEUMATIC MEANS CONNECTED TO THE DRIVE SUPPORT MEANS AND TO THESTATIONARY MEANS TO INDIVIDUALLY SWINGABLY MOVE SAID SUPPORT MEANS IN ANARCUATE PATH DOWNWARDLY AND UPWARDLY TO LOCATE THE GRINDING SURFACE ONSAID SUPPORT MEANS INTO AND OUT OF ENGAGEMENT WITH THE LOGS.